Vacuum operated pump



Oct. 6, 1964 J. F. PRIBONIC VACUUM OPERATED PUMP Filed June 29, 1961 2Sheets-Sheet l INV EN 1 OR. JOHN E PRIB ONIC HIS ATTORNEY Oct. 6, 1964J. F. PRIBONIC 3,151,805

vacuum OPERATED PUMP Filed June 29, 1961 -2 Sheets-Sheet 2 INVENTOR. 4Jfll/fi f. PR/BON/C ms ATT'OR/YE United States Patent 3,151,895 VAQl 1UM GPERATED FUR IF John F. Frihonic, Dayton, Gino, assignor to GeneralMotors Corporation, Detroit, Mich, a corporation of Delaware Filed lune29, 1961, Ser. No. 126,454 1 Claim. (Cl. 239-52) This invention relatesto a vacuum operated pump that is particulmly useful in compressing airfor use in air pressure actuated devices.

An object of the invention is to provide a vacuum operated fluid pump,particularly of the diaphragm operated type, wherein the pump isprovided with a pa r of opposed and coaxially aligned pistons andcylinders with the cylinders and pistons being valved in a manner thatthe pump can compress fluids in two stages with the fluid compressed inthe first stage be g delivered to the second stage through an axialpassage provided in the piston rod that connects the pistons togetherand also connects the pistons to the diaphragm of the pump.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to the accompanyingdrawings wherein a preferred embodiment of the present invention isclearly shown.

In the drawings:

FIGURE 1 is an elevational view of a pump incorporating features of thisinvention.

FIGURE 2 is a cross sectional view taken along line 2-2 of FIGURE 1.

FIGURE 3 is a partial cross sectional view taken along line 3--3 ofFIGURE 1 to illustrate the valving for operating the pump.

FIGURE 4 is a perspective view of the valve element that controlsoperation of the pump.

FIGURE 5 is an elevational view of an insert element used in the valveelement shown in FIGURE 4.

FIGURE 6 is a cross sectional view taken along line 6- i of FIGURE 7illustrating a part of the operating mechanism for the control valve ofthe pump.

FIGURE 7 is a partial elevational view or" the pump similar to FIGURE 1but with the valve operating mechanism illustrated in a position inwhich it is ready to move from the position shown in FIGURE 1 to theposition shown in FIGURE 9.

FIGURE 8 is a cross sectional view taken along line 8-8 of FIGURE 1illustrating certain of the valve passages for the pump.

FIGURE 9 is a partial elevational view similar to FIG- URE 1 wherein thevalve operating mechanism has been moved to its opposite position.

FIGURE 10 is a cross sectional view taken along line Ill-16 of FIGURE 9.

FIGURE 11 is a cross sectional view taken along line 11-11 of FIGURE 7illustrating the porting for operating the pump.

In this invention the pump comprises a first housing member it? and asecond housing member 11 that cooperate to form a closed chamber that isdivided into two compartments l2 and 13 by means of a flexible diaphragm14 having its periphery secured between the flanged portions 15 and 16of the respective housing members.

The housing It has a first cylinder 17 formed as an integral partthereof while the housing ll has a second cylinder 18 formed as anintegral part of the housing 11.

The cylinder bore 19 of cylinder 17 receives a piston 2% while thecylinder bore 21 of cylinder 18 receives a piston 22. The pistons 29 and22 are connected together by piston rod means 23 that is formed of thetwo parts 230 and 23b, part 23a having a threaded end portion 24received in a mating threaded portion in the part 2317. The threadedportion 24 extends through a central opening in the diaphragm l4 and apair of diaphragm clamping plates and 126 are retained on opposite sidesof the diaphragm between the parts 23a and 23b of the piston rod 23.

The cylinder 17 has a first valve chamber 25 that also includes a fluidinlet port 26 provided in the fitting 27. The inlet port 26 is closed bya first valve member 28 retained on its seat on fitting 27 by thecompression spring 29. The valve chamber 25 is open to the cylinder bore19 so that movement of the piston 24 in a leftward direction, as viewedin FIGURE 2, will draw air in through the inlet port 26.

The piston member 2% has a second valve chamber 343 that has a fittingmember 31 positioned therein by a snap ring 32 and has a discharge port33 therein through which pressurized fluid is discharged from thecylinder bore 19. The discharge port 33 is closed by a second valvemember 34 retained on a seat on the fitting member 31 by means of thecompression spring 335. The valve chamber 3% is open to the axial bore35 provided through the piston rod members 23:; and 23b for delivery ofpressurized fluid into this axial bore 35 from the cylinder bore 19 whenthe piston 2 moves in a righthand direction, as viewed in FIGURE 2.

The piston member 22 has a third valve chamber 36 that receives a thirdvalve member 37 seated upon a valve seat 33 formed at the end of theaxial passage 35, the valve member 37 being retained on the seat by thecompression spring 3?. The valve chamber as is open to the cylinder bore21 for flow of pressurized fluid from the passage 35 in the piston rodinto the cylinder bore 21 as the piston 22 moves a righthand direction,as viewed in FIGURE 2.

The cylinder 18 has a fourth valve chamber 49 hat has a fitting member41 provided with a discharge port 42 from cylinder bore 21 closed by avalve member 43 as held on a seat on the member 41 by the compressionspring 44, valve member 43 allowing fluid under pressur to pass from thecylinder chamber 21 into the conduit passage 4-5 provided in the fitting46 when the piston 22 moves in a lefthand direction, as viewed in FIGURE2.

It will be noted that all four valve members 28, 34 3'7 and 43 arepositioned on the axis of the cylinders 13 and 17 and coaxial therewithand that all of the valves open in one common direction and close in theopposite common direction so that fluid flow is unidirectional from theinlet 26 to the discharge conduit 45 in compressing fluid in stages,first in the cylinder bore 19 and thence in the cylinder bore 21 in thereciprocating stroke of the pistons 29 and 22. The arrangement providesfor a pump having all of the flow passages contained within the pump sothat no exterior conduits will be necessary to conduct pressurized fluidfrom the first stage compression chamber 19 to the second stagecompression chamber 21.

The pistons 20 and 22 are reciprocated in their respective cylinderbores by means of the diaphragm 14 as it moves from a position shown inFIGURE 2 to a position shown in FIGURE 10, the compartments 12 and 13being connected alternately with a vacuum or subatmospheric pressuresource while the opposite compartment is connected with atmosphere toobtain thereby a pressure differential at opposite sides of thediaphragm effective alternately to drive the diaphragm 14 in a lefthanddirection when chamber 12 is open to atmosphere and compartment 13 isconnected with a vacuum source and then to drive the diaphragm in arighthand direction to the position shown in FIGURE when compartment 13is at atmosphere pressure and compartment 12 is connected with thevacuum source.

The housing member 19 has a port 50 adapted for connection with a sourceof vacuum or subatmosphere pressure, such as the vacuum manifold on aninternal combustion engine of an automotive vehicle. The housing 10 isalso provided with two ports 51 and 52 positioned equidistantly at eachside of the vacuum port 59, port 51 being connected with compartment 12and port 52 being connected with compartment 13 by means of a portextension 53 providing in the housing member 11, as shown in FIGURE 11.

The housing member 19 has a planar face 54 on which a valve member 55 ispositioned as pivotally mounted thereon by a pivot screw 56, as shown inFIGURE 6. The valve member 55 is preferably of a semi-hard rubbermaterial so that it will not produce undesired clicking noise whenengaging the stops 57 and 58 in movement alternately from the positionshown in FIGURE 1 to that shown in FIGURE 9 in a manner hereinafterdescribed. To reduce the friction of movement of the planar face 59 ofthe valve 55 over the planar surface 54 of the housing member 10, aninsert member 6%, more specifically shown in FIGURE 5, is placed in thevalve member 55, the insert being formed of Teflon or other suitableself-lubricating plastic material or nylon. The insert member 6%) has apair of ports 61 and 62 that also provide ports through the valve member55, as shown in FIGURE 11. These ports 61 and 62 are adapted to alignalternately with the ports 51 and 52 in the housing wall and therebyalternately connect the chambers 12 and 13 with atmosphere.

The insert member 60 also has a recessed chamber 65 that communicateswith the vacuum or subatmosphere port 50 in the housing wall and isadapted to alternately connect the port 59 with the port 51 as shown inFIG- URE 11 when the valve member 55 is in the position shown in FIGURE1, or to connect the port 50 with the port 52 when the valve member 55is in the position as shown in FIGURE 9, and thereby alternately connectchambers 12 and 13 with the vacuum or subatmosphere port 50. From FIGURE11 it will be apparent that when chamber 12 is connected with thesubatmosphere port 50, chamber 13 will be connected with atmosphere, andthat when the valve member 55 shifts to its opposite position, thatchamber 13 will then be connected with the subsatmosphere or vacuum port50 while chamber 12 is connected with atmosphere and thereby alternatelyeffect a pressure differential at opposite sides of the diaphragm 14- toalternately move it from the position shown in FIGURE 2 to the positionshown in FIGURE 10 and thereby reciprocate the pistons 20 and 22 intheir respective cylinders 19 and 21.

The valve member 55 is shifted alternately from the position shown inFIGURE 1 to the position shown in FIGURE 9 by a mechanism that isactuated by reciprocable movement of the piston 2%.

As mentioned above, provision of a low coeflicient of friction plasticinsert member between the planar face 59 of the valve 55 and the planarsurface 54 of the housing member 10 effectively produces a smallerresultant force resisting the valve shifting mechanism to be moreparticularly set forth in the following portion of 4 the specification.The overall efficiency of the compressor is thereby improved.

The piston 20 has radial annular shoulder portions 70 and 71 that engagea finger member 72 secured on a rock shaft 73 pivotally mounted in theextension 74 of the housing member 1% as shown in FIGURE 6. Thus the endportion 75 of the rock shaft 73 oscillates from a position shown inFIGURE 1 to a position shown in FIGURE 9 as the shoulder portions 70 and71 alternately engage the finger 72 and move it from the position shownin FIGURE 2 to the position shown in FIG- URE 10.

The end portion 75 of the rock shaft 73 extends through a lever 76through a slot 77, lever 76 being pivoted on housing portion 74 by meansof a pivot screw 78. Thus the lever 76 is oscillated about the pivot 78from the position shown in FIGURE 1 to the position shown in FIGURE 9 inaccordance with oscillation of rock shaft 73. V

The free end of the lever 76 has a slot 178 through which a pin 79extends from the secondary lever 8i) that is carried on the pivot screw56 which also supports the valve member 55 as shown in FIGURE 6.Oscillation of the lever '76 by the rock shaft 73 also occasionsoscillation of the intermediate member 80 about the pivot screw 56 fromthe position shown in FIGURE 1 to the position shown in FIGURE 9. Acompression spring extends between the end portion 75 of the rock shaftand the pin 79 mounted on the intermediate member St), so that as thelever 76 moves from the position shown in FIGURE 1 through a positionshown in FIG- URE 7, the spring 35 moves over the axis center of thepivot screw 56 resulting in the snap action movement of the intermediatemember 86 to engage the valve 55 and move it rapidly from the positionshown in FIG- URE 1 to the position shown in FIGURE 9 and to thereby,reverse the porting of the chambers 12 and 13 in the manner heretoforedescribed.

The intermediate member 80 is adapted to engage the stop lugs 81 and 82provide at opposite sides of the Valve 55 when oscillating the valvemember between the positions shown in FIGURE 1 and FIGURE 9 as themember 89 is carried alternately back and forth by the lever 76.

While the embodiment of the present invention as herein disclosed,constitutes a preferred form, it is to be understood that other formsmight be adopted.

What is claimed is as follows:

In a pump, in combination, a housing forming a chamher, a flexiblediaphragm extending transversely of said chamber for dividing it intofirst and second compartments, said housing including cylinder means atopposite sides of said diaphragm, piston means in each of said cylindermeans, piston rod means connecting each of said piston means andconnected to said diaphragm for reciprocation thereby of said pistonmeans in said cylinder means, said piston means and piston rod meanshaving a passageway directed axially therethrough interconnecting saidcylinder means, means defining first and second ports in said housingcommunicating said first and second compartments respectively withatmosphere, means defining a third port in said housing adapted to beconnected to a source of subatmospheric pressure, a movable valvingelement sealingly engaging said housing including means therein foralternately connecting said third port with one of said first and secondports while leaving another of said first and second ports exposed toatmosphere to effect a pressure differential across said diaphragm forreciprocating said piston means, a pair of spaced stop means forlimiting the movement of said valving element, valve actuator meansoperatively associated with said piston means for moving said valvingelement to effect the alternate intercommunication of said first andsecond ports with atmosphere and said third port, said valving elementand stop means being 5 6 of relatively resiliently yieldable material todamp click- References Cited in the file of this patent ing noises uponoperative engagement with one another, UNITED STATES PATENTS saidvalving element including a portion of low coefficient of frictionplastic material supported in sliding 862867 Eggleston Z 1907 2,630,102Osburn Mar. 3, 1953 sealing engagement with said housing, said valvingelement portion having passageway means therein for com- FOREIGN PATENTSmunicating said first and second ports with said third 198,219 Gre tBritai May 31, 1923 port upon movement of said valving element between744,024 France Apr. 11, 1933 said stop means. 86,538 Norway Sept. 24,1955

